Pagination problem

Question

I have two custom rewrite rules:

add_rewrite_rule('foo/bar/?', 'index.php?post_type=foo', 'top');
add_rewrite_rule('foo/bar/([a-z]+)/?', 'index.php?post_type=foo&bar=$matches[1]', 'top');

Which gives me posts that match a custom variable bar. However, I want to handle pagination too, thus when a number succeeds /bar/ wordpress should treat it as a page number. I wrote:

add_rewrite_rule('foo/bar/([0-9]+)/?', 'index.php?post_type=foo&paged=$matches[1]', 'top');

In my custom function which is attached to pre_get_posts, I process the page number:

if($query->get('paged')) {
    $query->set('paged', intval($query->get('paged')));
}

However, when user accesses, say, foo/bar/2, wordpress automatically appends /page/2/, (e.g. in the address bar I get the following URL: foo/bar/2/page/2/).

Although the pagination itself works fine (I get the desired records as expected for each page) this /page/n/ messes up my links on the page and it is an unnecessary duplication in my url. How can I get rid of it?

Answer 1

The function redirect_canonical() is 'responsible' for your problem.

Your default WordPress pagination (with core functions) is not gonna work if you do this, but you can filter out the pagination for your particular custom url:

add_filter( 'redirect_canonical', 'wp230913_canonical', 10, 2 );

function wp230913_canonical( $redirect_url, $requested_url ) {
    if ( preg_match( "#foo/bar/[0-9]+/page/[0-9]+#", $redirect_url ) ) {
        return $requested_url;
    }

    return $redirect_url;
}

My recomandation is to change the pagination base for the whole site, changing $wp_rewrite->pagination_base